METHOD FOR DETERMINING UNSTATIONARY HEAT FLOW Russian patent published in 2023 - IPC G01K17/06 

FIELD: measuring technology.

SUBSTANCE: invention relates to measuring technology, to the field of thermometry and methods for measuring non-stationary heat flux. The proposed method for measuring non-stationary heat flow can be used in various fields of industry, energy and other areas of the national economy in the study of heat transfer processes, the measurement of heat transfer from surfaces, in the manufacture of metal heat-insulating screens, the study of the thermal state of parts in metallurgy, the development and optimization of radiators in electronics. equipment, in the fire service to analyze the overall picture of the emergency. A method for determining a non-stationary heat flux is proposed, including determining the change in the temperature of an object over time in the presence of a directed non-stationary heat flux, according to which electrodes are preliminarily placed on the surface of the measured object, which is electrically conductive. Further, by passing electric current through the electrodes at a frequency of ω₀, a skin layer is formed in the near-surface layer of the measured object. The impedance Z[jω_0, T_s(t)] of the skin layer is measured, by which the electrical resistance R[ω_0,T_s(t)] is determined, taking into account the preliminary calibration of the temperature dependence of the resistance R=ƒ(T) at a given frequency ω₀ for the specific material of the measured object. According to the electrical resistance R[ω_0,T_s(t)] of the skin layer, non-stationary changes in temperature Ts(t) over time on the surface of the measured object are determined and the non-stationary heat flux q(t) is determined by the formula:

where Ts(t) - non-stationary temperature on the surface of the measured object; c - specific heat capacity of the measured object; ρ - specific thermal resistance of the measured object; λ - coefficient of thermal conductivity of the measured object; - fractional derivative of half order with respect to time.

EFFECT: increasing the speed of measurement of non-stationary heat flux in time.

1 cl, 3 dwg